Solvent extraction and quality assessment of fish oil from Patin Catfish (Pangasius Hypophthalmus)

Abstract

Fish oil was extracted from Patin catfish (Pangasius hypophthalmus) using environment friendly solvent extraction method in which acetone/ ethyl acetate mixture was employed. Design of Experiments (DOE) was employed to study the effect of process parameters such as temperature (25–50 °C), extraction time (5–15 minutes) and acetone to ethyl acetate ratio (1–4 v/v) towards the oil yield. The optimum condition was then determined by response surface methodology (RSM) coupled with central composite design (CCD). Results revealed that optimum oil yield of 10.84 % can be achieved by using acetone to ethyl acetate ratio of 2, at 45 °C in 13 minutes of extraction time. The functional group analysis of fish oil extracted was performed by using Fourier Transform Infrared Spectroscopy (FTIR). It was found that functional groups presented in fish oil were aromatics, alkenes, carboxylic acids, alkanes, esters, saturated aliphatic, alcohols and ethers. The quality of fish oil was analyzed by determining acid value, peroxide value and p-anisidine value. The acid value, peroxide value and p-anisidine value of fish oil determined were 1.415 ± 0.04363 mg KOH/ g oil (< 5 mg KOH/ g oil), 3.333 ± 0.1333 mEq/ kg oil (≤ 5 mEq/ kg oil) and 11.19 ± 0.8995 (≤ 20) respectively and the results were within the acceptable standard value.